It supposes it somehow learns your name from interaction with the site (Marios here is a placeholder)
and then sends your name and your fingerprint to the server
Next time u visit the site, it either shows you:
- Marios (the system didn't recognize you)
- your typed name (the system did recognize you)
It works pretty good with Google Chrome (even if you try Incognito Window),
and a bit less reliable with MacOS' Safari
It doesn't store any cookies, so no GDPR is violated =)